HEPA filter

So-called HEPA filters (High-Efficiency-Particulate-Airfilter), i.e. filters for particulate matter, have proven themselves over decades in a large number of facilities, as they reduce the airborne spread of particles and organisms such as viruses and bacteria. In times of Corona, such a filter is more important than ever. HEPA filters can remove even the smallest microbes in the air, reducing harmful airborne germs. This includes not only cold or flu viruses, but also dust, pollen, mold pores and smoke particles. However, HEPA filters cannot actively kill living organisms. They filter the particles and hold them back in the medium.

The efficiency of the HEPA filter is indicated by the particle size with the greatest penetration. The particle size is typically 0.1-0.2 micrometers. Bacteria and viruses are often smaller, but typically attach to larger particles. The size of the coronavirus, on the other hand, is around 150 nanometers. In order to get a efficient cut-off of 99.995% To ensure this, at least filter class H14 filters are required. While these filters are used in many hygienic areas, they would create too high a differential pressure in most other HVAC applications.

The filter media used for the HEPA filter are ultra-fine microglass papers that are pleated to form filter media surfaces that are 40 to 100 times the surface area. This results in a particularly long flow, which supports the diffusion cut-off of the submicron particles.

Air purifiers can also be used to further improve air quality. They are very effective in improving overall air quality. The advantage of air purifiers is that they achieve a significantly higher filter efficiency in rooms in which it would otherwise not be possible. This makes it possible to reduce the contamination in a room by around 90% or more.

Used filters should be changed at least every 6 months and only with full protective equipment (long sleeves, long trousers, gloves, breathing mask, protective goggles). This ensures good maintenance and good hygiene of the air conditioning technology.